Positive contact ignition assembly



March 15, 1949. 'r. R. SHEARER POSITIVE CONTACT IGNITION ASSEMBLY FiledMay 21. 194i 1 Can-1 FIG-"'5 Thom s '2. Shearer {Enveabor QtbornegPatented Mar. 15, 1949 lclnim.

invention relates toignition systems of.

internal combustion engines and, more speciflcally. to improvements indistributors and spark plug ignition connectors for automobiles.

It is well known that the condition of the ignition system of aninternal combustion engine is a very important factor in achieving highengine efliciency and satisfactory operation. Yet, the units now on themarket are subject to -many troubles which interfere with engineoperation, particularly during adverse weather conditions or after aprolonged driving period. For example. the ignition cables leading intothe distributor begin to corrode at the ends and lose theireffectiveness in providing good electrical contact. The same is truewith the spark plug ends of the cables, and such conventionalconnections are readily shorted by small quantities of water which maybe splashed or blown in under the hood of the car. Also, the rotor andinner distributor contacts are readily corroded or burned out by arcing,and combustion eiiiciency is reduced considerably thereby.

It is the purpose of this invention to eliminate such detrimentalconditions and to provide an ignition system which will give highethciency and maintain such high efllciency over extended periods oftime.

The invention may be more readily understood by reference to the drawingin which Figure 1 shows a cross-sectional side view of a distributor capand rotor employing features of the present invention; Figure 2 is aside view, partly in cross section, of the spark plug connection. of thepresent invention, while Figure 3 is a bottom view of an innerdistributor contact provided with a clip ofthe present invention.-

Referring again to the drawing, numeral I represents a distributor cap,generally made of insulating plastic, and having a series of wells 2around the upper part for housing the ends of the ignition cables II.also provided on the to for housing the end of the cable leading to thefixed contact H of rotor l0. Molded into the bottom of wells 2 andcentral well 3 are metal (copper or brass) contacts 8 and contact 8respectively, which contact clips I! attached to the ends of cables I]and through which are threaded and spread out the inner stranded copperwires IQ of thecables. Contacts 5 extend (by means of sections 4)through the top of the cap and terminate with contacts I which makeelectrical contact with moving contact I! of rotor i0. Likewise, contact I projects by means of section 8 through A central well 3 is thecenter of the cap and terminates with a button contact on which ridesstationary contact ll of rotor l0. Heretofore, there has been a spacebetween well 2 and cable H which allowed ingress of water, dust, and thelike and these elements gradually accelerated the corrosion of the endsof wires I! and clips l0, resulting in rapid loss'in emc'iency of thecontact. This difficulty has been eliminated in the present invention byproviding a movable sleeve I8 of soft or resilient rubber or plasticwhich may be slid into the space between the well and the outside of thecable, thereby sealing the otherwise exposed air space.

Another difflculty, previously mentioned, has been the poor contact,during service, obtained between rotor contact I5 and contacts 6 of thecap. This has been attributed to the fact that contact I5 is usually ofsteel while'contacts 6 are of copper. Both of these metals tend to fuseand spatter on arcing and they both tend to corrode considerably inpresence of moisture, which effects greatly reduce their contactefllciency One feature of the present invention is to eliminate theseconditions by making contact.

with a contact surface of molybdenum which has been found to be highlyresistant to burning or spattering by high voltage arcs and toatmospheric corrosion accelerated by the presence of ozone created bythe arc.

This molybdenum surface I may be attached to contacts 6 by metalcladding or spot welding of a sheet of molybdenum on contact 6 (afterthelatter has been reduced in thickness by millin grinding or filing toallow for the insertion of the molybdenum sheet or strip and stillmaintain proper clearance with relation to rotor contact l5). However,it 'is preferableto employ clips 33 of molybdenum which may be slippedover contacts 6. These clips preferably comprise a strip of molybdenumof Qt" or ,4 thickness, more or less, and are shaped to providesubstantially flat portion 1 contacting rotor contact i5, and concavelycurved or circular arc sections 33 which grip the back portion ofcontact 6. Space 34 is provided to allow for variations in dimensions ofthe periphery of contact 6. These clips are slipped over contacts 6 andare held in place due to the tension at curved ends 33. As to the rotorcontact, it is preferred to'employ a strip of molybdenum l5 which ismaintained inelectrical contact with spring arm 13 by rivet I 4.However, it is possible to weld or clad or otherwise attach a strip ofmolybdenum only on the contacting tip of strip I5, the tip preferablybeing rounded to conform to the arc of travel of the rotor.

To eliminate difliculties with spark plug connections, end 28 ofignition cable 29 has attached thereto clip 21 from the center of whichpro trude wire ends I 9. This end bearing the clip is inserted in theupper portion 25 of the double connector 28, the bottom portion 23 ofwhich is clippedonto the spark plug terminal 22. Sections 25 and 23 ofthe double connector 26 are joined together, although there is usuallyprovided a central opening between the two sections to allow for egressof air, etc. Over this whole assembly is slipped a flexible sleeve 30 ofrubber, plastic or other insulating material, the sleeve being longenough to adequately cover the upper ends of the connections and tightenough to snugly fit over the outside of the cable 29. The lower end ofthe sleeve extends over the bottom ends of the connections andterminates at about the half-way portion 2 I .of the insulator on sparkplug 20, the lit being a-snug one. However, the sleeve should not extendtoo far down the plug as to become burned by the heat. By this means,moisture, dust, corrosive gases, and other interfering elements are keptout of the contact surfaces, thereby maintaining a high' contactefiiciency.

By means of the molybdenum contacts provided in the distributor, arcingis greatly elimihated, and particularly, vaporization of the metal isreduced and consequent wear at the arc, which results in poor starting.By means of the plastic sleeves, moisture and other corrosive andforeign agents are kept out away from the contact surfaces, givingpositive contact for considerably long periods of time. These sleevesare easily in stalled. The spark plug end is slipped over the plug andthe end of the sleeve, which usually is curled under, is pulled up byflexing the rubber, and then allowed to snap back inte place.

With an assembly such as that described, it has been possible to travel50ml miles easily with out any visible evidence oi. burning of contactsor corrosion. Due to the high contact efliciency maintained. it has beenfound that the life of the condenser is extended considerably thereby.The eflectiveness oi! this assembly is evidenced by the fact that easein starting, pick-up, and mileage improvement remain practicallyundiminished for long driving periods, and a noticeable diiierence ingetaway and hotter spark are observed when a change is made from theconventional assembly to that of the present invention. Also, by actualexperience, it has been found that the distributor make-and-break pointshave shown no burning or pitting over extended periods of driving time.

I claim:

In a distributor-to-cable-to-spark plug ignition system employing wellsprojecting from the top of the distributor cap for housing the cableends. semicircular distributor cap contacts intermittently contacting arotating rotor contact, and a double connector snapping on the sparkplug terminal and holding an endof the cable, the improvement comprisinga D-shaped molybdenum strip, broken atthe curved portion and slightlycurved at the broken ends to provide tension and forming a secure, snugfitting clip over each semi-circular distributor cap contact.

THOMAS R. SHEARER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,338,989 Lang May 4, 19201,569,224 Berthold Sept. 23, 3924 1,658,713 Ir'liliei' Feb. 7, 19281,898,6i6t Ridge Feb. 21, 1933 2,1616% Spengler Aug. 1, 1939 2,253,221Barnum et al Aug. 19, 194i 2,3 ifi,455 Hartzeli Mar. 7, i944

